New Debate about Vehicle Miles Travelled Fee

Recent weeks have seen renewed debate about how to pay for transportation investment. The National Financing Commission released a report recommending an increase in the gas tax and a transition in the next decade to a system based on vehicle miles travelled (VMT). Around the same time, Transportation Secretary LaHood commented that he was willing to consider a VMT charge as a revenue mechanism – a comment that the Obama administration quickly smacked down and backed away from. This was a surprising move that does little to advance a reasonable discussion of how to actually pay for transportation investment.

The basic issues, as we have partly laid out in previous posts, are these:

1. There is a popular myth that the public fully pays for transportation infrastructure via the gas tax. This is false. As the Finance Commission reports, people pay nowhere near the full direct and indirect costs of transportation.


2. Transportation infrastructure is not only deteriorating, it is not being used efficiently. Charging people more of the actual cost of their use can preclude the need for more investment. Either people pay upfront with higher fees, or they pay later through higher general or indirect taxes, and it is cheaper to pay upfront.


3. If we do not raise enough revenue through user fees like a VMT charge, we face the issue of whether to spend money from the general fund. This would be a foolish approach because it severs the connection between payment and use.


4. The gas tax is unsustainable. As the primary revenue source, in the short term it needs to be increased if we want to invest adequately in transportation. In the medium term (5-20 years), it needs to be phased out because changing technologies will limit the revenue it raises.

So we arrive at discussion of the VMT charge. The administration’s dismissal of a VMT charge flies in the face of broad consensus in the transportation sector. Without proposing an alternative revenue source, it seems that the administration either does not believe that more money should be invested in transportation, or that more investment should be paid for from the general fund. The first possibility is contradicted by the administration’s own emphasis in the stimulus bill of the public value of investing in transportation. The second possibility is simply poor policy.

At a time when the country needs to focus on efficient spending, a policy that funds transportation from the general fund is the most costly and least efficient approach. It voids the principle of “user pay” and ensures that transportation infrastructure will be used in the most inefficient way (i.e. continued traffic congestion).

It is not that a VMT charge is the only viable user fee available, but it is a logical and reasonable one. To dismiss it off the cuff without a discussion of the alternatives is to preempt a thoughtful debate of best practices. For those reasons, we have certainly not heard the last of a VMT charge.

The Cost of Gas and Transit

A recent article in the Los Angeles Times highlighted some signs that transit ridership is declining as gas prices fall. Although much of the ridership evidence is anecdotal at this point, given the roughly 50% drop in gas prices over the last few months a return to cars would not be unexpected. However, more data will need to be gathered (and numbers from recent months more fully analyzed) before any firm conclusions can be made about driving trends. Even then the implications may not be clear, because several questions cloud the situation.

The first x-factor is the weak economy. Economic growth or weakness has in the past correlated quite closely with vehicle miles travelled (VMT) - with growth increasing VMT and weakness hurting it -although vigorous debate still exists about which way the causation flows. In fact, recent events may yield some insight for this debate. For example, a year ago the economy was still fairly healthy and gas prices were rising sharply – two forces that should pull VMT in opposite directions. In recent months the economy has been hit hard, yet gas prices have also plummeted, once again creating forces that usually pull VMT in opposite directions. The data is not yet available to clearly assess how this is playing out, but it will be interesting to look at more closely in the near future.

The second x-factor is uncertainty about future gas prices. As we have discussed in past blogs, a decision between driving and transit can be made day-to-day, thus gas prices have an instant short-term impact on transit usage. But expectations of higher prices in the future may be continuing to shape longer term consumer decisions about vehicle purchases and the location of housing. If that is the case, a full rebound to previous VMT levels (per capita) may not occur, despite current cheap gas.

The LA Times article underlines the importance of having a flexible transportation system with multiple ways to get from point A to point B. But more than just current gas prices are at work in influencing transit usage today, and it would be a mistake to draw conclusions about the long-term health and viability of transit from recent anecdotal evidence. 

-Daniel Lewis